Ruthenium-catalyzed ortho-arylation of acetanilides with aromatic boronic acids: an easy route to prepare phenanthridines and carbazoles

The highly regioselective ortho-arylation of acetanilides with aromatic boronic acids in the presence of a Ru(II) complex (3 mol%), AgSbF6 (12 mol%), Cu(OTf)(2) (20 mol%) and Ag2O (1.0 eq.) is described. Later, ortho-arylated acetanilides were converted into phenanthridine and carbazole derivatives by using Ph3PO and Tf2O or palladium or Cu(OTf)(2) catalysts.